/**
 * @(#)StringUtils.java
 *
 * Copyright (c) 2010 sinba. All Rights Reserved.
 */
package com.sinba.common.util;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Locale;
import java.util.Properties;
import java.util.Set;
import java.util.StringTokenizer;
import java.util.TreeSet;


/**
 * Miscellaneous string utility methods. Mainly for internal use
 * within the framework; consider Jakarta's Commons Lang for a more
 * comprehensive suite of string utilities.
 *
 * <p>This class delivers some simple functionality that should really
 * be provided by the core Java String and StringBuffer classes, such
 * as the ability to replace all occurrences of a given substring in a
 * target string. It also provides easy-to-use methods to convert between
 * delimited strings, such as CSV strings, and collections and arrays.
 *
 * @version 1.00 2007-4-23
 * @author <a href="mailto:sinbawang@msn.com">Sinba Wang</a>
 */
@SuppressWarnings("unchecked")
public abstract class StringUtils {

    private static final String FOLDER_SEPARATOR = "/";
    private static final String WINDOWS_FOLDER_SEPARATOR = "\\";
    private static final String TOP_PATH = "..";
    private static final String CURRENT_PATH = ".";
    private static final char EXTENSION_SEPARATOR = '.';

    protected StringUtils() {
        super();
    }

    //---------------------------------------------------------------------
    // General convenience methods for working with Strings
    //---------------------------------------------------------------------

    /**
     * Check that the given String is neither <code>null</code> nor of length 0.
     * Note: Will return <code>true</code> for a String that purely consists of whitespace.
     * <p><pre>
     * StringUtils.hasLength(null) = false
     * StringUtils.hasLength("") = false
     * StringUtils.hasLength(" ") = true
     * StringUtils.hasLength("Hello") = true
     * </pre>
     * @param str the String to check (may be <code>null</code>)
     * @return <code>true</code> if the String is not null and has length
     * @see #hasText(String)
     */
    public static boolean hasLength(String str) {

        return ((str != null) && (str.length() > 0));
    }

    /**
     * Check whether the given String has actual text.
     * More specifically, returns <code>true</code> if the string not <code>null<code>,
     * its length is greater than 0, and it contains at least one non-whitespace character.
     * <p><pre>
     * StringUtils.hasText(null) = false
     * StringUtils.hasText("") = false
     * StringUtils.hasText(" ") = false
     * StringUtils.hasText("12345") = true
     * StringUtils.hasText(" 12345 ") = true
     * </pre>
     * @param str the String to check (may be <code>null</code>)
     * @return <code>true</code> if the String is not <code>null</code>, its length is
     * greater than 0, and is does not contain whitespace only
     * @see java.lang.Character#isWhitespace
     */
    public static boolean hasText(String str) {

        if (!hasLength(str)) {

            return false;
        }

        int strLen = str.length();

        for (int i = 0; i < strLen; i++) {

            if (!Character.isWhitespace(str.charAt(i))) {

                return true;
            }
        }

        return false;
    }

    /**
     * Check whether the given String contains any whitespace characters.
     * @param str the String to check (may be <code>null</code>)
     * @return <code>true</code> if the String is not empty and
     * contains at least 1 whitespace character
     * @see java.lang.Character#isWhitespace
     */
    public static boolean containsWhitespace(String str) {

        if (!hasLength(str)) {

            return false;
        }

        int strLen = str.length();

        for (int i = 0; i < strLen; i++) {

            if (Character.isWhitespace(str.charAt(i))) {

                return true;
            }
        }

        return false;
    }

    /**
     * Trim leading and trailing whitespace from the given String.
     * @param str the String to check
     * @return the trimmed String
     * @see java.lang.Character#isWhitespace
     */
    public static String trimWhitespace(String str) {

        if (!hasLength(str)) {

            return str;
        }

        StringBuffer buf = new StringBuffer(str);

        while ((buf.length() > 0) && Character.isWhitespace(buf.charAt(0))) {

            buf.deleteCharAt(0);
        }

        while ((buf.length() > 0)
                && Character.isWhitespace(buf.charAt(buf.length() - 1))) {

            buf.deleteCharAt(buf.length() - 1);
        }

        return buf.toString();
    }

    /**
     * Trim leading whitespace from the given String.
     * @param str the String to check
     * @return the trimmed String
     * @see java.lang.Character#isWhitespace
     */
    public static String trimLeadingWhitespace(String str) {

        if (!hasLength(str)) {

            return str;
        }

        StringBuffer buf = new StringBuffer(str);

        while ((buf.length() > 0) && Character.isWhitespace(buf.charAt(0))) {

            buf.deleteCharAt(0);
        }

        return buf.toString();
    }

    /**
     * Trim trailing whitespace from the given String.
     * @param str the String to check
     * @return the trimmed String
     * @see java.lang.Character#isWhitespace
     */
    public static String trimTrailingWhitespace(String str) {

        if (!hasLength(str)) {

            return str;
        }

        StringBuffer buf = new StringBuffer(str);

        while ((buf.length() > 0)
                && Character.isWhitespace(buf.charAt(buf.length() - 1))) {

            buf.deleteCharAt(buf.length() - 1);
        }

        return buf.toString();
    }

    /**
     * Trim <i>all</i> whitespace from the given String:
     * leading, trailing, and inbetween characters.
     * @param str the String to check
     * @return the trimmed String
     * @see java.lang.Character#isWhitespace
     */
    public static String trimAllWhitespace(String str) {

        if (!hasLength(str)) {

            return str;
        }

        StringBuffer buf = new StringBuffer(str);
        int index = 0;

        while (buf.length() > index) {

            if (Character.isWhitespace(buf.charAt(index))) {

                buf.deleteCharAt(index);
            } else {

                index++;
            }
        }

        return buf.toString();
    }

    /**
     * Trim <i>redundant</i> whitespaces from the given string,
     * only preserving one in-between whitespace in the given string.
     *
     * @param str the String to check
     * @return the trimmed String
     *
     * @see java.lang.Character#isWhitespace
     */
    public static String trimRedundantInbetweenWhitespace(String str) {

        if (!hasLength(str)) {

            return str;
        }

        StringBuffer buf = new StringBuffer(str);

        while ((buf.length() > 0) && Character.isWhitespace(buf.charAt(0))) {

            buf.deleteCharAt(0);
        }

        while ((buf.length() > 0)
                && Character.isWhitespace(buf.charAt(buf.length() - 1))) {

            buf.deleteCharAt(buf.length() - 1);
        }

        int index = 0;
        int mark = 0;

        while (buf.length() > index) {

            if (Character.isWhitespace(buf.charAt(index))) {

                if (mark == 0) {

                    mark = 1;
                    index++;

                    continue;
                }

                buf.deleteCharAt(index);
            } else {

                mark = 0;
                index++;
            }
        }

        return buf.toString();
    }

    /**
     * Test if the given String starts with the specified prefix,
     * ignoring upper/lower case.
     * @param str the String to check
     * @param prefix the prefix to look for
     * @see java.lang.String#startsWith
     */
    public static boolean startsWithIgnoreCase(String str, String prefix) {

        if ((str == null) || (prefix == null)) {

            return false;
        }

        if (str.startsWith(prefix)) {

            return true;
        }

        if (str.length() < prefix.length()) {

            return false;
        }

        String lcStr = str.substring(0, prefix.length()).toLowerCase();
        String lcPrefix = prefix.toLowerCase();

        return lcStr.equals(lcPrefix);
    }

    /**
     * Test if the given String ends with the specified suffix,
     * ignoring upper/lower case.
     * @param str the String to check
     * @param suffix the suffix to look for
     * @see java.lang.String#endsWith
     */
    public static boolean endsWithIgnoreCase(String str, String suffix) {

        if ((str == null) || (suffix == null)) {

            return false;
        }

        if (str.endsWith(suffix)) {

            return true;
        }

        if (str.length() < suffix.length()) {

            return false;
        }

        String lcStr = str.substring(str.length() - suffix.length())
                          .toLowerCase();
        String lcSuffix = suffix.toLowerCase();

        return lcStr.equals(lcSuffix);
    }

    /**
     * Count the occurrences of the substring in string s.
     * @param str string to search in. Return 0 if this is null.
     * @param sub string to search for. Return 0 if this is null.
     */
    public static int countOccurrencesOf(String str, String sub) {

        if ((str == null) || (sub == null) || (str.length() == 0)
                || (sub.length() == 0)) {

            return 0;
        }

        int count = 0;
        int pos = 0;
        int idx = 0;

        while ((idx = str.indexOf(sub, pos)) != -1) {

            ++count;
            pos = idx + sub.length();
        }

        return count;
    }

    /**
     * Replace all occurences of a substring within a string with
     * another string.
     * @param inString String to examine
     * @param oldPattern String to replace
     * @param newPattern String to insert
     * @return a String with the replacements
     */
    public static String replace(String inString, String oldPattern,
        String newPattern) {

        if (inString == null) {

            return null;
        }

        if ((oldPattern == null) || (newPattern == null)) {

            return inString;
        }

        StringBuffer sbuf = new StringBuffer();

        // output StringBuffer we'll build up
        int pos = 0; // our position in the old string
        int index = inString.indexOf(oldPattern);

        // the index of an occurrence we've found, or -1
        int patLen = oldPattern.length();

        while (index >= 0) {

            sbuf.append(inString.substring(pos, index));
            sbuf.append(newPattern);
            pos = index + patLen;
            index = inString.indexOf(oldPattern, pos);
        }

        sbuf.append(inString.substring(pos));

        // remember to append any characters to the right of a match
        return sbuf.toString();
    }

    /**
     * Delete all occurrences of the given substring.
     * @param pattern the pattern to delete all occurrences of
     */
    public static String delete(String inString, String pattern) {

        return replace(inString, pattern, "");
    }

    /**
     * Delete any character in a given string.
     * @param charsToDelete a set of characters to delete.
     * E.g. "az\n" will delete 'a's, 'z's and new lines.
     */
    public static String deleteAny(String inString, String charsToDelete) {

        if ((inString == null) || (charsToDelete == null)) {

            return inString;
        }

        StringBuffer out = new StringBuffer();

        for (int i = 0; i < inString.length(); i++) {

            char c = inString.charAt(i);

            if (charsToDelete.indexOf(c) == -1) {

                out.append(c);
            }
        }

        return out.toString();
    }

    //---------------------------------------------------------------------
    // Convenience methods for working with formatted Strings
    //---------------------------------------------------------------------

    /**
     * Quote the given String with single quotes.
     * @param str the input String (e.g. "myString")
     * @return the quoted String (e.g. "'myString'"),
     * or <code>null<code> if the input was <code>null</code>
     */
    public static String quote(String str) {

        return ((str != null) ? ("'" + str + "'") : null);
    }

    /**
     * Turn the given Object into a String with single quotes
     * if it is a String; keeping the Object as-is else.
     * @param obj the input Object (e.g. "myString")
     * @return the quoted String (e.g. "'myString'"),
     * or the input object as-is if not a String
     */
    public static Object quoteIfString(Object obj) {

        return ((obj instanceof String) ? quote((String) obj) : obj);
    }

    /**
     * Unqualify a string qualified by a '.' dot character. For example,
     * "this.name.is.qualified", returns "qualified".
     * @param qualifiedName the qualified name
     */
    public static String unqualify(String qualifiedName) {

        return unqualify(qualifiedName, '.');
    }

    /**
     * Unqualify a string qualified by a separator character. For example,
     * "this:name:is:qualified" returns "qualified" if using a ':' separator.
     * @param qualifiedName the qualified name
     * @param separator the separator
     */
    public static String unqualify(String qualifiedName, char separator) {

        return qualifiedName.substring(qualifiedName.lastIndexOf(separator)
            + 1);
    }

    /**
     * Capitalize a <code>String</code>, changing the first letter to
     * upper case as per {@link Character#toUpperCase(char)}.
     * No other letters are changed.
     * @param str the String to capitalize, may be <code>null</code>
     * @return the capitalized String, <code>null</code> if null
     */
    public static String capitalize(String str) {

        return changeFirstCharacterCase(str, true);
    }

    /**
     * Uncapitalize a <code>String</code>, changing the first letter to
     * lower case as per {@link Character#toLowerCase(char)}.
     * No other letters are changed.
     * @param str the String to uncapitalize, may be <code>null</code>
     * @return the uncapitalized String, <code>null</code> if null
     */
    public static String uncapitalize(String str) {

        return changeFirstCharacterCase(str, false);
    }

    private static String changeFirstCharacterCase(String str,
        boolean capitalize) {

        if ((str == null) || (str.length() == 0)) {

            return str;
        }

        StringBuffer buf = new StringBuffer(str.length());

        if (capitalize) {

            buf.append(Character.toUpperCase(str.charAt(0)));
        } else {

            buf.append(Character.toLowerCase(str.charAt(0)));
        }

        buf.append(str.substring(1));

        return buf.toString();
    }

    /**
     * Extract the filename from the given path,
     * e.g. "mypath/myfile.txt" -> "myfile.txt".
     * @param path the file path (may be <code>null</code>)
     * @return the extracted filename, or <code>null</code> if none
     */
    public static String getFilename(String path) {

        if (path == null) {

            return null;
        }

        int separatorIndex = path.lastIndexOf(FOLDER_SEPARATOR);

        return ((separatorIndex != -1)
        ? path.substring(separatorIndex + 1) : path);
    }

    /**
     * Extract the filename extension from the given path,
     * e.g. "mypath/myfile.txt" -> "txt".
     * @param path the file path (may be <code>null</code>)
     * @return the extracted filename extension, or <code>null</code> if none
     */
    public static String getFilenameExtension(String path) {

        if (path == null) {

            return null;
        }

        int sepIndex = path.lastIndexOf(EXTENSION_SEPARATOR);

        return ((sepIndex != -1) ? path.substring(sepIndex + 1) : null);
    }

    /**
     * Strip the filename extension from the given path,
     * e.g. "mypath/myfile.txt" -> "mypath/myfile".
     * @param path the file path (may be <code>null</code>)
     * @return the path with stripped filename extension,
     * or <code>null</code> if none
     */
    public static String stripFilenameExtension(String path) {

        if (path == null) {

            return null;
        }

        int sepIndex = path.lastIndexOf(EXTENSION_SEPARATOR);

        return ((sepIndex != -1) ? path.substring(0, sepIndex) : path);
    }

    /**
     * Apply the given relative path to the given path,
     * assuming standard Java folder separation (i.e. "/" separators);
     * @param path the path to start from (usually a full file path)
     * @param relativePath the relative path to apply
     * (relative to the full file path above)
     * @return the full file path that results from applying the relative path
     */
    public static String applyRelativePath(String path, String relativePath) {

        int separatorIndex = path.lastIndexOf(FOLDER_SEPARATOR);

        if (separatorIndex != -1) {

            String newPath = path.substring(0, separatorIndex);

            if (!relativePath.startsWith(FOLDER_SEPARATOR)) {

                newPath += FOLDER_SEPARATOR;
            }

            return newPath + relativePath;
        } else {

            return relativePath;
        }
    }

    /**
     * Normalize the path by suppressing sequences like "path/.." and
     * inner simple dots.
     * <p>The result is convenient for path comparison. For other uses,
     * notice that Windows separators ("\") are replaced by simple slashes.
     * @param path the original path
     * @return the normalized path
     */
    public static String cleanPath(String path) {

        String pathToUse = replace(path, WINDOWS_FOLDER_SEPARATOR,
                FOLDER_SEPARATOR);

        // Strip prefix from path to analyze, to not treat it as part of the
        // first path element. This is necessary to correctly parse paths like
        // "file:core/../core/io/Resource.class", where the ".." should just
        // strip the first "core" directory while keeping the "file:" prefix.
        int prefixIndex = pathToUse.indexOf(":");
        String prefix = "";

        if (prefixIndex != -1) {

            prefix = pathToUse.substring(0, prefixIndex + 1);
            pathToUse = pathToUse.substring(prefixIndex + 1);
        }

        String[] pathArray = delimitedListToStringArray(pathToUse,
                FOLDER_SEPARATOR);
        List pathElements = new LinkedList();
        int tops = 0;

        for (int i = pathArray.length - 1; i >= 0; i--) {

            if (CURRENT_PATH.equals(pathArray[i])) {

                break;

                // Points to current directory - drop it.
            } else if (TOP_PATH.equals(pathArray[i])) {

                // Registering top path found.
                tops++;
            } else {

                if (tops > 0) {

                    // Merging path element with corresponding to top path.
                    tops--;
                } else {

                    // Normal path element found.
                    pathElements.add(0, pathArray[i]);
                }
            }
        }

        // Remaining top paths need to be retained.
        for (int i = 0; i < tops; i++) {

            pathElements.add(0, TOP_PATH);
        }

        return prefix
        + collectionToDelimitedString(pathElements, FOLDER_SEPARATOR);
    }

    /**
     * Compare two paths after normalization of them.
     * @param path1 First path for comparizon
     * @param path2 Second path for comparizon
     * @return whether the two paths are equivalent after normalization
     */
    public static boolean pathEquals(String path1, String path2) {

        return cleanPath(path1).equals(cleanPath(path2));
    }

    /**
     * Parse the given locale string into a <code>java.util.Locale</code>.
     * This is the inverse operation of Locale's <code>toString</code>.
     * @param localeString the locale string, following
     * <code>java.util.Locale</code>'s toString format ("en", "en_UK", etc).
     * Also accepts spaces as separators, as alternative to underscores.
     * @return a corresponding Locale instance
     */
    public static Locale parseLocaleString(String localeString) {

        String[] parts = tokenizeToStringArray(localeString, "_ ", false,
                false);
        String language = ((parts.length > 0) ? parts[0] : "");
        String country = ((parts.length > 1) ? parts[1] : "");
        String variant = ((parts.length > 2) ? parts[2] : "");

        return ((language.length() > 0)
        ? new Locale(language, country, variant) : null);
    }

    //---------------------------------------------------------------------
    // Convenience methods for working with String arrays
    //---------------------------------------------------------------------

    /**
     * Append the given String to the given String array, returning a new array
     * consisting of the input array contents plus the given String.
     * @param array the array to append to (can be <code>null</code>)
     * @param str the String to append
     * @return the new array (never <code>null</code>)
     */
    public static String[] addStringToArray(String[] array, String str) {

        if (ObjectUtils.isEmpty(array)) {

            return new String[] {str};
        }

        String[] newArr = new String[array.length + 1];

        System.arraycopy(array, 0, newArr, 0, array.length);
        newArr[array.length] = str;

        return newArr;
    }

    /**
     * Check whether the given strings array contains the given string.
     *
     * @param array the given strings array
     * @param str the element to look for
     * @param ignoreCase the boolean variable to denote ignore case or not
     *
     * @return <code>true</code> if found, <code>false</code> else
     */
    public static boolean contains(String[] array, String str,
        boolean ignoreCase) {

        if ((array != null) && (array.length > 0)) {

            if (ignoreCase) {

                for (String strInArray : array) {

                    if (strInArray.equalsIgnoreCase(str)) {

                        return true;
                    }
                }
            } else {

                for (String strInArray : array) {

                    if (strInArray.equals(str)) {

                        return true;
                    }
                }
            }
        }

        return false;
    }

    /**
     * Concatenate the given String arrays into one,
     * with overlapping array elements included twice.
     * <p>The order of elements in the original arrays is preserved.
     * @param array1 the first array (can be <code>null</code>)
     * @param array2 the second array (can be <code>null</code>)
     * @return the new array (<code>null</code> if both given arrays were <code>null</code>)
     */
    public static String[] concatenateStringArrays(String[] array1,
        String[] array2) {

        if (ObjectUtils.isEmpty(array1)) {

            return array2;
        }

        if (ObjectUtils.isEmpty(array2)) {

            return array1;
        }

        String[] newArr = new String[array1.length + array2.length];

        System.arraycopy(array1, 0, newArr, 0, array1.length);
        System.arraycopy(array2, 0, newArr, array1.length, array2.length);

        return newArr;
    }

    /**
     * Merge the given String arrays into one, with overlapping
     * array elements only included once.
     * <p>The order of elements in the original arrays is preserved
     * (with the exception of overlapping elements, which are only
     * included on their first occurence).
     * @param array1 the first array (can be <code>null</code>)
     * @param array2 the second array (can be <code>null</code>)
     * @return the new array (<code>null</code> if both given arrays were <code>null</code>)
     */
    public static String[] mergeStringArrays(String[] array1,
        String[] array2) {

        if (ObjectUtils.isEmpty(array1)) {

            return array2;
        }

        if (ObjectUtils.isEmpty(array2)) {

            return array1;
        }

        List result = new ArrayList();

        result.addAll(Arrays.asList(array1));

        for (int i = 0; i < array2.length; i++) {

            String str = array2[i];

            if (!result.contains(str)) {

                result.add(str);
            }
        }

        return toStringArray(result);
    }

    /**
     * Intersect the given String arrays, with overlapping array elements only included once.
     * <p>The order of elements in the original arrays is preserved (with the exception of overlapping
     * elements, which are only included on their first occurence).
     *
     * @param array1 the first array (can be <code>null</code>)
     * @param array2 the second array (can be <code>null</code>)
     * @param ignoreCase the boolean variable to denote ignore case or not
     *
     * @return the new array (<code>null</code> if both given arrays were <code>null</code>)
     */
    public static String[] intersectStringArrays(String[] array1,
        String[] array2, boolean ignoreCase) {

        if (ObjectUtils.isEmpty(array1) && ObjectUtils.isEmpty(array2)) {

            return null;
        }

        if (ObjectUtils.isEmpty(array1)) {

            return array2;
        }

        if (ObjectUtils.isEmpty(array2)) {

            return array1;
        }

        List result = new ArrayList();

        for (int i = 0; i < array1.length; i++) {

            String strInArray1 = array1[i];

            if (contains(array2, strInArray1, ignoreCase)) {

                result.add(strInArray1);
            }
        }

        return toStringArray(result);
    }

    /**
     * Turn given source String array into sorted array.
     * @param array the source array
     * @return the sorted array (never <code>null</code>)
     */
    public static String[] sortStringArray(String[] array) {

        if (ObjectUtils.isEmpty(array)) {

            return new String[0];
        }

        Arrays.sort(array);

        return array;
    }

    /**
     * Copy the given Collection into a String array.
     * The Collection must contain String elements only.
     * @param collection the Collection to copy
     * @return the String array (<code>null</code> if the passed-in
     * Collection was <code>null</code>)
     */
    public static String[] toStringArray(Collection collection) {

        if (collection == null) {

            return null;
        }

        return (String[]) collection.toArray(new String[collection.size()]);
    }

    /**
     * Remove duplicate Strings from the given array.
     * Also sorts the array, as it uses a TreeSet.
     * @param array the String array
     * @return an array without duplicates, in natural sort order
     */
    public static String[] removeDuplicateStrings(String[] array) {

        if (ObjectUtils.isEmpty(array)) {

            return array;
        }

        Set set = new TreeSet();

        for (int i = 0; i < array.length; i++) {

            set.add(array[i]);
        }

        return toStringArray(set);
    }

    /**
     * Split a String at the first occurrence of the delimiter.
     * Does not include the delimiter in the result.
     * @param toSplit the string to split
     * @param delimiter to split the string up with
     * @return a two element array with index 0 being before the delimiter, and
     * index 1 being after the delimiter (neither element includes the delimiter);
     * or <code>null</code> if the delimiter wasn't found in the given input String
     */
    public static String[] split(String toSplit, String delimiter) {

        if (!hasLength(toSplit) || !hasLength(delimiter)) {

            return null;
        }

        int offset = toSplit.indexOf(delimiter);

        if (offset < 0) {

            return null;
        }

        String beforeDelimiter = toSplit.substring(0, offset);
        String afterDelimiter = toSplit.substring(offset
                + delimiter.length());

        return new String[] {beforeDelimiter, afterDelimiter};
    }

    /**
     * Take an array Strings and split each element based on the given delimiter.
     * A <code>Properties</code> instance is then generated, with the left of the
     * delimiter providing the key, and the right of the delimiter providing the value.
     * <p>Will trim both the key and value before adding them to the
     * <code>Properties</code> instance.
     * @param array the array to process
     * @param delimiter to split each element using (typically the equals symbol)
     * @return a <code>Properties</code> instance representing the array contents,
     * or <code>null</code> if the array to process was null or empty
     */
    public static Properties splitArrayElementsIntoProperties(
        String[] array, String delimiter) {

        return splitArrayElementsIntoProperties(array, delimiter, null);
    }

    /**
     * Take an array Strings and split each element based on the given delimiter.
     * A <code>Properties</code> instance is then generated, with the left of the
     * delimiter providing the key, and the right of the delimiter providing the value.
     * <p>Will trim both the key and value before adding them to the
     * <code>Properties</code> instance.
     * @param array the array to process
     * @param delimiter to split each element using (typically the equals symbol)
     * @param charsToDelete one or more characters to remove from each element
     * prior to attempting the split operation (typically the quotation mark
     * symbol), or <code>null</code> if no removal should occur
     * @return a <code>Properties</code> instance representing the array contents,
     * or <code>null</code> if the array to process was <code>null</code> or empty
     */
    public static Properties splitArrayElementsIntoProperties(
        String[] array, String delimiter, String charsToDelete) {

        if (ObjectUtils.isEmpty(array)) {

            return null;
        }

        Properties result = new Properties();

        for (int i = 0; i < array.length; i++) {

            String element = array[i];

            if (charsToDelete != null) {

                element = deleteAny(array[i], charsToDelete);
            }

            String[] splittedElement = split(element, delimiter);

            if (splittedElement == null) {

                continue;
            }

            result.setProperty(splittedElement[0].trim(),
                splittedElement[1].trim());
        }

        return result;
    }

    /**
     * Tokenize the given String into a String array via a StringTokenizer.
     * Trims tokens and omits empty tokens.
     * <p>The given delimiters string is supposed to consist of any number of
     * delimiter characters. Each of those characters can be used to separate
     * tokens. A delimiter is always a single character; for multi-character
     * delimiters, consider using <code>delimitedListToStringArray</code>
     * @param str the String to tokenize
     * @param delimiters the delimiter characters, assembled as String
     * (each of those characters is individually considered as delimiter).
     * @return an array of the tokens
     * @see java.util.StringTokenizer
     * @see java.lang.String#trim()
     * @see #delimitedListToStringArray
     */
    public static String[] tokenizeToStringArray(String str,
        String delimiters) {

        return tokenizeToStringArray(str, delimiters, true, true);
    }

    /**
     * Tokenize the given String into a String array via a StringTokenizer.
     * <p>The given delimiters string is supposed to consist of any number of
     * delimiter characters. Each of those characters can be used to separate
     * tokens. A delimiter is always a single character; for multi-character
     * delimiters, consider using <code>delimitedListToStringArray</code>
     * @param str the String to tokenize
     * @param delimiters the delimiter characters, assembled as String
     * (each of those characters is individually considered as delimiter)
     * @param trimTokens trim the tokens via String's <code>trim</code>
     * @param ignoreEmptyTokens omit empty tokens from the result array
     * (only applies to tokens that are empty after trimming; StringTokenizer
     * will not consider subsequent delimiters as token in the first place).
     * @return an array of the tokens (<code>null</code> if the input String
     * was <code>null</code>)
     * @see java.util.StringTokenizer
     * @see java.lang.String#trim()
     * @see #delimitedListToStringArray
     */
    public static String[] tokenizeToStringArray(String str,
        String delimiters, boolean trimTokens, boolean ignoreEmptyTokens) {

        if (str == null) {

            return null;
        }

        StringTokenizer st = new StringTokenizer(str, delimiters);
        List tokens = new ArrayList();

        while (st.hasMoreTokens()) {

            String token = st.nextToken();

            if (trimTokens) {

                token = token.trim();
            }

            if (!ignoreEmptyTokens || (token.length() > 0)) {

                tokens.add(token);
            }
        }

        return toStringArray(tokens);
    }

    /**
     * Take a String which is a delimited list and convert it to a String array.
     * <p>A single delimiter can consists of more than one character: It will still
     * be considered as single delimiter string, rather than as bunch of potential
     * delimiter characters - in contrast to <code>tokenizeToStringArray</code>.
     * @param str the input String
     * @param delimiter the delimiter between elements (this is a single delimiter,
     * rather than a bunch individual delimiter characters)
     * @return an array of the tokens in the list
     * @see #tokenizeToStringArray
     */
    public static String[] delimitedListToStringArray(String str,
        String delimiter) {

        if (str == null) {

            return new String[0];
        }

        if (delimiter == null) {

            return new String[] {str};
        }

        List result = new ArrayList();

        if ("".equals(delimiter)) {

            for (int i = 0; i < str.length(); i++) {

                result.add(str.substring(i, i + 1));
            }
        } else {

            int pos = 0;
            int delPos = 0;

            while ((delPos = str.indexOf(delimiter, pos)) != -1) {

                result.add(str.substring(pos, delPos));
                pos = delPos + delimiter.length();
            }

            if ((str.length() > 0) && (pos <= str.length())) {

                // Add rest of String, but not in case of empty input.
                result.add(str.substring(pos));
            }
        }

        return toStringArray(result);
    }

    /**
     * Convert a CSV list into an array of Strings.
     * @param str the input String
     * @return an array of Strings, or the empty array in case of empty input
     */
    public static String[] commaDelimitedListToStringArray(String str) {

        return delimitedListToStringArray(str, ",");
    }

    /**
     * Convenience method to convert a CSV string list to a set.
     * Note that this will suppress duplicates.
     * @param str the input String
     * @return a Set of String entries in the list
     */
    public static Set commaDelimitedListToSet(String str) {

        Set set = new TreeSet();
        String[] tokens = commaDelimitedListToStringArray(str);

        for (int i = 0; i < tokens.length; i++) {

            set.add(tokens[i]);
        }

        return set;
    }

    /**
     * Convenience method to return a Collection as a delimited (e.g. CSV)
     * String. E.g. useful for <code>toString()</code> implementations.
     * @param coll the Collection to display
     * @param delim the delimiter to use (probably a ",")
     * @param prefix the String to start each element with
     * @param suffix the String to end each element with
     */
    public static String collectionToDelimitedString(Collection coll,
        String delim, String prefix, String suffix) {

        if (CollectionUtils.isEmpty(coll)) {

            return "";
        }

        StringBuffer sb = new StringBuffer();
        Iterator it = coll.iterator();

        while (it.hasNext()) {

            sb.append(prefix).append(it.next()).append(suffix);

            if (it.hasNext()) {

                sb.append(delim);
            }
        }

        return sb.toString();
    }

    /**
     * Convenience method to return a Collection as a delimited (e.g. CSV)
     * String. E.g. useful for <code>toString()</code> implementations.
     * @param coll the Collection to display
     * @param delim the delimiter to use (probably a ",")
     */
    public static String collectionToDelimitedString(Collection coll,
        String delim) {

        return collectionToDelimitedString(coll, delim, "", "");
    }

    /**
     * Convenience method to return a Collection as a CSV String.
     * E.g. useful for <code>toString()</code> implementations.
     * @param coll the Collection to display
     */
    public static String collectionToCommaDelimitedString(Collection coll) {

        return collectionToDelimitedString(coll, ",");
    }

    /**
     * Convenience method to return a String array as a delimited (e.g. CSV)
     * String. E.g. useful for <code>toString()</code> implementations.
     * @param arr the array to display
     * @param delim the delimiter to use (probably a ",")
     */
    public static String arrayToDelimitedString(Object[] arr, String delim) {

        if (ObjectUtils.isEmpty(arr)) {

            return "";
        }

        StringBuffer sb = new StringBuffer();

        for (int i = 0; i < arr.length; i++) {

            if (i > 0) {

                sb.append(delim);
            }

            sb.append(arr[i]);
        }

        return sb.toString();
    }

    /**
     * Convenience method to return a String array as a CSV String.
     * E.g. useful for <code>toString()</code> implementations.
     * @param arr the array to display
     */
    public static String arrayToCommaDelimitedString(Object[] arr) {

        return arrayToDelimitedString(arr, ",");
    }
}